Zhou Jingxuan, Zhou Jingyuan, Wan Zhong, Qian Qi, Ren Huaying, Yan Xingxu, Zhou Boxuan, Zhang Ao, Pan Xiaoqing, Fang Wuzhang, Ping Yuan, Sofer Zdenek, Huang Yu, Duan Xiangfeng
Department of Materials Science and Engineering, University of California, Los Angeles, Los Angeles, CA, USA.
Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA, USA.
Nature. 2025 Jun 25. doi: 10.1038/s41586-025-09147-z.
Tailoring magnetic ordering in solid-state materials is essential for emerging spintronics. However, substitutional lattice doping in magnetic semiconductors is often constrained by the low solubility of magnetic elements, limiting the maximum achievable doping concentration (for example, less than 5%) and ferromagnetic ordering temperature. The intercalation of magnetic elements in layered two-dimensional atomic crystals (2DACs) without breaking in-plane covalent bonds offers an alternative approach to incorporate a much higher concentration of magnetic atoms (for example, up to 50%) beyond the typical solubility limit. However, commonly used chemical and electrochemical intercalation methods are largely confined to a few isolated examples so far. Here we report a general two-step intercalation and cation-exchange strategy to produce a library of highly ordered magnetic intercalation superlattices (MISLs) with tunable magnetic ordering. Monovalent transition-metal cations Cu and Ag, divalent magnetic cations Mn, Fe, Co and Ni, and trivalent rare-earth cations Eu and Gd have been successfully incorporated into group-VIB 2DACs, including MoS, MoSe, MoTe, WS, WSe and WTe, and group-IVB, -VB, -IIIA, -IVA and -VA 2DACs, including TiS, NbS, NbSe, TaS, InSe, SnSe, BiSe and BiTe. We show that these MISLs can be prepared with tunable concentrations of magnetic intercalants, enabling tailored magnetic ordering across a diverse array of functional 2DACs, including semiconductors, topological insulators, and superconductors. This work establishes a versatile material platform for both fundamental investigations and spintronics applications.
在固态材料中定制磁有序对于新兴的自旋电子学至关重要。然而，磁性半导体中的替代晶格掺杂常常受到磁性元素低溶解度的限制，这限制了可实现的最大掺杂浓度（例如，小于5%）和铁磁有序温度。在层状二维原子晶体（2DACs）中插入磁性元素而不破坏面内共价键，提供了一种替代方法，可纳入远超典型溶解度极限的更高浓度磁性原子（例如，高达50%）。然而，到目前为止，常用的化学和电化学插入方法在很大程度上仅限于少数孤立的例子。在此，我们报告一种通用的两步插入和阳离子交换策略，以制备一系列具有可调磁有序的高度有序磁性插入超晶格（MISLs）。单价过渡金属阳离子Cu和Ag、二价磁性阳离子Mn、Fe、Co和Ni以及三价稀土阳离子Eu和Gd已成功纳入VIB族2DACs，包括MoS、MoSe、MoTe、WS、WSe和WTe，以及IVB族、VB族、IIIA族、IVA族和VA族2DACs，包括TiS、NbS、NbSe、TaS、InSe、SnSe、BiSe和BiTe。我们表明，这些MISLs可以通过可调浓度的磁性插入剂来制备，从而在包括半导体、拓扑绝缘体和超导体在内的各种功能性2DACs中实现定制的磁有序。这项工作为基础研究和自旋电子学应用建立了一个通用的材料平台。
